The present description relates generally to wireless communication, and more specifically to methods, systems, and apparatus to compensate for impairments of a wireless device. Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be multiple-access systems capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power). Examples of such multiple-access systems include code-division multiple access (CDMA) systems, time-division multiple access (TDMA) systems, frequency-division multiple access (FDMA) systems, and orthogonal frequency-division multiple access (OFDMA) systems.
Generally, a wireless multiple-access communications system may include a number of base stations, each simultaneously supporting communication for multiple mobile devices. Base stations may communicate with mobile devices on downstream and upstream links (i.e., over wireless channels). Each base station has a coverage range, which may be referred to as the coverage area of the cell. During system operation of the base station, various components may introduce impairments into a wireless device (e.g., due to thermal and temporal variations). Common impairments may be associated with analog image rejection filters that can be asymmetric across a spectrum of interest, and in-phase/quadrature (I/Q) modulators. The former may cause unwanted droops in the passband of a transmitted signal, and the latter may inject gain and phase variations between the I/Q components of the transmitted signal. These impairments may deteriorate the quality of wireless signals transmitted between the base station and a mobile device, thereby reducing the effective data rate between the base station and the mobile device.